I have a 90g skimmerless, I run an oxydator. http://saltwater-conversion.com/prod...hting-oxydator

How bad could the stuff be, little bit ago there was a post about gargling with it.

I think the biggest issue is you can't predict how it will affect all organics in a system :)

Can't predict how, but for sure u can predict it will affect organic so every system is different 😏

Not in the sense that they all contain an abundance of organic life which all marine systems do , good and bad :)

It's quite common in ponding products that are designed to control algae. I have a tub of this stuff for my pond. Unfortunately it is in a low concentration. Something like 10% H2O2. Dez uses something like 35% H2o2 on his pond and probably dilutes that for his reef tank.

I've never used it for my tank as I've never had any algae issues.

Where did you get yours Don?

Where is Dez? Somebody tag him! Probably on a beach somewhere..

My thought is that this acts like ozone, and not just for algae issues. Water clarity, sand cleanliness, etc. Again, conceptually the idea is sound, just not sure what the risks are. I guess that's the issue, we don't know. Maybe I'll try it and see if anything implodes :)

H2O2 Dosing?
 

At this point I can say with pretty high confidence that hydrogen peroxide is both one of the most useful and safest tools in a reefers toolkit.

It's not completely without risk, but you have to dose a massive amount to harm anything. I use both 3% and 29% depending on what I need it for. Stupidly, I've been storing my 29% in a 3% bottle from shoppers with a home made sharpie label on it. I messed up once and grabbed the wrong bottle and used 45mL of it my tank. A few of my acros browned out for a few days, but that was about it.

If you're spot treating cyano or Dino's with the pumps off, 3% works great. If you need to really clean off a section of more persistent algae, or are looking to broadcast dose to systemically inhibit cyano, 29% (or 30 if you can get it) is probably easier to use. You can also dilute 29% however you want. I'll sometimes make 7% solutions cuz they have a bit more kick when it comes to killing algae, and you can use more of it.

ETA: when I used the 45 mL of 29% by accident it was with the pumps off and about 50 gallons of water drained from the display. I don't think that amount would have caused a reaction of it was full and the return pump had been on

I know my LFS guy used it to spot kill algae, but I hadn't thought of regular use to just sparkle things up a bit. Sounds like it would work for that. Maybe?